So you have density, infectivity, mortality, and recovery – four factors interrelated as fundamentally as heat, tinder, spark, and fuel. Brought together in the critical measure of each, the critical balance, they produce fire: epidemic.

If SARS had conformed to the perverse pattern of presymptomatic infectivity, its 2003 emergence wouldn’t be a case history in good luck and effective outbreak response. It would be a much darker story.

From the ecological point of view an outbreak can be defined as an explosive increase in the abundance of a particular species that occurs over a relatively short period of time.” Then, in the same bland tone, he noted: “From this perspective, the most serious outbreak on the planet earth is that of the species Homo sapiens.

From this perspective, the most serious outbreak on the planet earth is that of the species Homo sapiens.

If you look at the world from the point of view of a hungry virus,” the historian William H. McNeill has noted, “or even a bacterium – we offer a magnificent feeding ground with all our billions of human bodies, where, in the very recent past, there were only half as many people. In some 25 or 27 years, we have doubled in number. A marvelous target for any organism that can adapt itself to invading us.

We should appreciate that these recent outbreaks of new zoonotic diseases, as well as the recurrence and spread of old ones, are part of a larger pattern, and that humanity is responsible for generating that pattern. We should recognize that they reflect things that we’re doing, not just things that are happening to us. We should understand that, although some of the human-caused factors may seem virtually inexorable, others are within our control.

The purpose of this book is not to make you more worried. The purpose of this book is to make you more smart.

The result will be gradual transmutation of heritable forms, and adaptation to circumstances, by a process of selective culling. Eventually he gave the crank a name: natural selection. Twenty years passed after the E notebook entry. The world heard nothing about natural selection.

Any tiny little thing that people do,” Dwyer said, if it makes them different from one another, from the idealized standard of herd behavior, “is going to reduce infection rates.

Human-caused ecological pressures and disruptions are bringing animal pathogens ever more into contact with human populations, while human technology and behavior are spreading those pathogens ever more widely and quickly. There are three elements to the situation.